Important volcanic activity is experienced in Colombia due to the fact that the country is located in an area where three tectonic plates interact: the Nazca Plate, the South American Plate and the Caribbean Plate. Due to this location, the list of volcanoes is long and many of them are active. Additionally, new areas with volcanic activity have been found in recent years.

Carlos, a graduate of Universidad EAFIT with a degree in Geology and who is currently conducting research in Mexico, based his final paper for the university on the study of volcanic rocks and deposits found on the surface and understanding how those rocks originate. His findings helped him conclude that magma-shaped materials produced by volcanoes along the Colombian territory share the same composition of a mixture of sediments from the Pacific Ocean and the terrestrial mantle.

This researcher explains that he took a number of rock samples from the eruptive centers of Santa Isabel volcano (In the Central Andes mountains) to geochemically analyze their total-rock composition and minerals. “I did this to know the concentration of the more abundant elements, which make up 99 percent of the rock, as well as the trace elements that make less than one percent. I also studied the geochemistry of the isotope ratios of a number of elements including Strontium (Sr) and Lead (Pb)”, he adds.

Through the data collected, the geologist could understand which processes take place in the depth of the volcano. “I started comparing these data with other volcanoes in the country, particularly with Cerro Machín. The volcano chemistry is very similar to the melting of the sediments found in the Colombian Pacific Ocean with the terrestrial mantle; all the chemical analysis showed that these rocks are the result of a mixture between these two components. Nazca Plate, which is beneath the South American Continental Plate undergoes a subduction process, adding these sediments as it enters the mantle, which in turn forms the molten products, meaning magna, which will then erupt in the Colombian volcanic craters”.

Background of the study

Carlos started his final undergraduate paper in October 2016. His ideas were conceptualized in Mexico, where he conducted some research activities, did the analysis and developed the hypothesis with the support of Arturo Gómez Tuena, professor at Universidad Autónoma de México (UNAM) and expert in the Faja Volcánica Trans-Mexicana, who has studied volcanic rocks in Mexico and around the world.

Carlos Errázuriz´s interest in the volcanic phenomenon was awakened when he was still a child. “When I was twelve, I climbed my first volcano, Santa Isabel, with my father. After that, we would go a couple of times every year and when I was 15 I went alone”.

According to Carlos, volcanoes tell a lot about the history of the Earth. From his point of view, those in Colombia “are formed within the tectonic framework of the volcanic arcs as a result of subduction, unfortunately the country has one of the least analyzed volcanic regions in the world. For this reason, the origin of our volcanoes is still under debate, it is not yet fully understood”.

Work in progress

Even though his findings have represented great advances in his area, they have also been controversial since they have elements and assertions that had previously not been presented. Rather, they contradict some of the studies conducted in this field. Carlos Errázuriz has presented his work in Congreso de Geología Colombiano (Colombian Geological Congress) and in the GSA Annual Meeting held in the United States of America.

From his point of view, trace elements and isotopes reveal very deep processes that occur in the geological layers: understanding the origin of these rocks helps us to understand volcanoes and their origin. “This study is important in order to analyze the system of the planet Earth. Amidst other issues, it allows us to get to know how continents are formed, which also supports human life. My objective is to translate this technical knowledge into information that can be disseminated: to get to know how many volcanoes we have, how active they are and, in this way, to decrease the probability of catastrophic events”.

His final paper, that received a mention of honor laureate during his graduation ceremony, is a life project of Carlos’: “I have some projects with Universidad EAFIT and Universidad Nacional de Colombia professors, where I am currently doing a master´s degree. My intention is to expand the volcanic complex database in order to clearly understand what it is happening. For example, sediments in Colombia have not yet been extensively analyzed, and that is the other part of my project, to understand these sediments. I am currently in Mexico working with professor Arturo Gómez in order to give continuity to this research.”